Indeed, this was essentially my line of thinking with the "Race and Class" post elsewhere... essentially, many of the "typical" demihuman traits are particular and common to most of the members of those races because they follow the same traditional training regimen... not necessarily because they possess the abilities innately due to their genes. They are acquired and earned through environment, not nature...
The primary argument against all the abilities being innate to the racial makeup is that the characters will not have them at 0-level… regardless of how old the character might be or how related his profession might be to the “racial” ability, only a few abilities are possessed and not earned until 1st level… abilities officially possessed at 0-level are noted with an asterisk.
Attack Modifier, Mighty Deeds, and sword and Board: All due to standard dwarven military training;
Infravision*: Innate to dwarves, and seems natural for a race that truly lives underground all the time (unlike elves and the smial-dwelling halflings);
Slow [Short]*: Innate;
Underground Skills: States explicitly that these skills are due to "long life living underground," not innate;
Luck: "applies to attack rolls... just as a warrior's does." Trained, not innate;
Magic, Caster Level, Supernatural Patrons: "Elves practice arcane magic sustained by traffic with otherworldly creatures.” Trained, not innate;
Infravision: Could be innate, but just as likely, due to the class description and lack of possessing it at 0-level, as being gained through their traffic with otherworldly types; (though the lack of possessing it at 0-level might be an oversight, as with the halfling’s “Small Size,” below);
Immunities: Same as Infravision;
Vulnerabilities*: Could be understood as due to the traffic with otherworldly beings, I went with it as being innate, to give the elf race a counterbalance like the slow speed of the dwarves and halflings;
Heightened Senses*: Again, could be due to traffic, but I went with this as being innate;
Luck: Long lifespan + practice with magic, not innate;
Two-Weapon Fighting: Training
Infravision*: Innate, and officially, the only racial ability a 0-level halfling has (IMC they don’t have infravision at all).
Small Size: This should be innate and possessed at 0-level; halflings don’t just shrink when going from 0 to 1st level, after all!
Stealth: Could be training, could be innate; in my version of the 0-level demihuman abilities, it is innate and related to their size, rather than Infravision.
Double Luck: This could, I suppose, be considered innate, in the stead of the Stealth or Infravision;
Luck Recovery: As the Thief gains essentially the same ability, this seems more a training than innate ability;
Good Luck Charm: This is the ability that every player who wants to play a “halfling thief” or other class would insist that, of course, it must be innate! However, if it were truly “innate,” the “one lucky charm halfling per party” rule could not stand. It is, as mentioned a “fickle thing governed by gods,” and thus not truly innate. The gods, it seems, smiles on halflings who follow their traditional cultural paths, not those who eschew these ways and follow other paths…
That’s why I go with the following innate abilities for 0-level demihumans:
Dwarf: Infravision and Short (base speed 20')
Elf: Heightened Senses and Iron Sensitivity
Halfling: Stealthy (+2 Sneak Silently and Hide in Shadows) and Short (base speed 20'), though officially it should be Infravision and Short, and the argument could readily go for Double Luck and Short… maybe Stouts have Infravision and Short, Tallfellows Stealthy and Short, and Hairfeet have Double Luck and Short…
Personal Gameblog: http://adventuresingaming2.blogspot.com